Meeting The Increasing Demand For Technologies That Enable Antibody Product Differentiation

BREDA, The Netherlands I August 6, 2013 I arGEN-X, a clinical stage biopharmaceutical company specialized in the creation and development of highly differentiated human antibody therapeutics, today announces the signing of its second non-exclusive license agreement for its antibody half-life extension technology, NHance™. Both licenses granted to date are with companies dedicated to developing and commercializing antibody-based therapeutics with clear clinical benefits.

Under the terms of these agreements, arGEN-X receives upfront technology access and annual license maintenance fees, in addition to clinical milestone payments and tiered royalties on product sales. No further details are being disclosed.

Commenting on today’s announcement, Tim Van Hauwermeiren, CEO of arGEN-X, said:

“Since our recent launch of NHance™, we have witnessed considerable interest from companies seeking to develop antibody therapeutics with best in class attributes. As a novel, validated approach to optimizing antibody pharmacokinetics, NHance™ delivers longer drug residence times in the body, enabling less frequent subcutaneous dosing, improved patient convenience and attractive pharmacoeconomics. In addition to applying NHance™ to our own pipeline programs, we intend to exploit our unique IP position by commercializing the technology both through arms length licensing and broader antibody discovery collaborations. We are therefore pleased to enter into these agreements and fully expect to generate further NHance™ partnerships in the future.”

About NHance™

NHance™is an arGEN-X proprietary technology capable of increasing the half life of a therapeutic antibody in the human systemic circulation. NHance™ achieves this through 2 specific mutations in the antibody Fc region (at His433 and Asn434), resulting in an improved affinity of antibody binding to the neonatal Fc receptor at acidic pH. This receptor is responsible for recycling the antibody within the human body. Enhanced antibody serum levels resulting from prolonged half-life may lead to a higher therapeutic effect, lower material requirements for the same therapeutic effect, and/or reduced dosing frequency. The technology may also further enhance antibody transport across mucosal barriers, enabling alternative routes of antibody product administration.

About arGEN-X   http://www.arGEN-X.com

arGEN-X is a clinical stage human therapeutic antibody company that is rapidly developing a product pipeline using its unique suite of antibody technologies. arGEN-X is creating first and best in class antibody therapeutics with highly differentiated target product profiles. Its therapeutic antibody programs, focused on cancer and autoimmune indications, are designed to deliver tangible benefits to patients with these diseases.

arGEN-X’ SIMPLE Antibody™ platform generates an unprecedented diversity of high quality human antibodies, enabling optimal product choice. SIMPLE Antibodies™ are able to address and modulate any disease target, including complex receptors and highly conserved targets often intractable with other antibody technologies. SIMPLE Antibody™ generated leads are further differentiated as products through enhancement of cell killing properties (POTELLIGENT®, licensed from BioWa Inc.) and optimization of circulation time and distribution in the body (NHance™). ArGEN-X is also developing ABDEG™ technology, to potentiate the clearance of disease-causing autoantibodies.

In January 2013, arGEN-X initiated a Phase Ib clinical trial for ARGX-110, its most advanced SIMPLE Antibody™ program modulating CD70 via a unique mode of action in hematological and virally-induced solid tumors, as well as in autoimmunity. A second CTA for ARGX-111, a novel anti-c-Met antibody to treat diverse solid tumors, will be filed later in 2013.

The SIMPLE Antibody™ platform is covered by broad patent claims, enjoys an independent, unencumbered patent position and is free of target gatekeeping restrictions.

SIMPLE stands for Superior Immunodiversity with Minimal Protein Lead Engineering.

arGEN-X™, SIMPLE Antibody™ and NHance™ are deposited trademarks of arGEN-X BV.

SOURCE: arGEN-X